The present invention relates to a device for transporting a printable material within a printing machine, and more particularly a device for transporting a printable material using vacuum.
Vacuum assisted material handling assemblies are often used for manipulating sheets of print material, such as paper, envelopes, labels, etc. In particular, vacuum assisted rollers are desirable in high-speed printing applications, where it is important that one sheet be picked-up and transported at a time. Contemporary vacuum assisted feeder heads use a rotatably mounted cylindrical body having surface apertures. The apertures are coupled to a vacuum source and are used to create a negative surface pressure for picking up and moving the print material. The ability of the feeder head to properly engage and retain pieces of print material is correlated to surface texture of the feeder head engagement surfaces, as well as the size and configuration of the apertures, the vacuum source and feeder head itself.
Variations in print material and general maintenance often demand changes in the surface texture or aperture configuration on the feeder head. For example, the material engagement surface of the feeder head may be worn down or a larger or different aperture is needed. However, in order to change or repair the surface texture or aperture configuration on the feeder head, traditionally the entire cylindrical feeder head body needs to be removed and replaced. Such repairs and/or changes are difficult and often involve the neighboring assembly in the printing apparatus. Some more recent feeder heads include an outer sleeve or plate that has its own apertures that align with the apertures on the more traditional feeder head. However, the outer sleeve/plate aperture profile is limited by the size and configuration of the underlying cylinder apertures. Thus, more extensive surface or aperture profile changes once require the replacement of the entire feeder head.
Thus, it is desirable to provide a device for transporting a printable material which overcomes the shortcomings found in the art of material transfer assemblies as set forth above while also providing improved structural and operating features.